The highest prefix allowed by the International System of Units (SI) is the “yotta”, for 24 zeroes
Scientists are lobbying for a new word to help them describe numbers larger than 1,000,000,000,000,000,000,000,000,000, amid concerns that the current system of units is insufficient. A campaign for “hella” to join the likes of “kilo”, “mega” and “giga” as an internationally accepted prefix is attracting growing support.
